The present application claims priority to Japanese Application No. P11-306129 filed Oct. 27, 1999, which application is incorporated herein by reference to the extent permitted by law.
1. Field of the Invention
This invention relates to a tubular-shaped battery.
2. Description of Related Art
Recently, an increasing number of electronic equipment are reduced in size and portable and can be run by batteries such as alkaline cells. In general, in order to vent a gas occurred in a battery on incorrectly charging the battery, a safety valve is provided in a portion of a battery sealing element to release the internal pressure in safety at a time point when the internal pressure in the battery is low.
The alkaline battery having the safety valve had a drawback that, if the battery is allowed to stand for prolonged time at elevated temperature, the safety valve itself undergoes chronological deterioration, such that the safety valve is actuated even if the internal pressure in the battery is low.
If the safety valve is actuated, leakage of the electrolytic solution contained in the battery occurs unavoidably. Should the leaking electrolytic solution be deposited e.g., on the skin, it is highly likely that the skin be thereby injured.
There is also known a battery in which a washer for preventing external shorting is mounted around the negative terminal. However, since this washer is not designed to completely cover the degassing hole of the negative terminal, it is not possible to prevent leakage of the electrolytic solution.
It is therefore an object of the present invention to provide a battery free of the above-described drawback of the prior art and to provide a battery capable of preventing leakage of the electrolytic solution.
According to the present invention, there is provided battery in which a positive electrode, a negative electrode and an electrolyte are arranged in a bottomed tubular battery case and in which an opening in the battery case is sealed by a battery lid having a degassing hole, wherein the degassing hole is covered by a sheathing member.
With the battery according to the present invention, in which the degassing hole formed in the battery lid is covered by the sheathing member to prevent the electrolytic solution from leaking through the degassing hole.
According to the present invention, the degassing hole formed in the battery case is covered by the sheathing member to prevent the leakage of the electrolytic solution through the degassing hole. Thus, the tubular battery of the present invention is extremely high in operational reliability.